The Structure of Practical Rationality

A way of behaving is a way to behave. It is a system of deriving recommendations of the form: ‘Such-and-such is the thing to do,’ from descriptions of the circumstances. So a way of behaving must be characterised normatively. For example, one of the rules characterising someone's way of behaving might be: ‘If you are in a supermarket doing the shopping and you need milk then the thing to do is to pick a carton of milk from the shelf.’ An input into such a system might be the fact that you are in a supermarket doing the shopping and needing milk, and the output would be the recommendation that picking a carton of milk from the shelf is the thing to do.

This looks like a rather illiberal conception of a way of behaving. It might be argued that a way of behaving should be characterised instead by recommendations of the form: ‘Such-and-such is a thing that may be done.’ For example, when choosing a carton of milk in a shop and faced with fifty similar cartons, the recommendation might be: ‘You may pick a carton which is third from the left in the shelf.’

Anthony Kenny has defended something like this idea, arguing that a system of practical recommendations characterising a way of behaving should be thought of as providing several alternative (and incompatible) recommendations in any situation. He argues that in a particular kind of situation there may be more than one response recommended, and that a way of behaving may be indifferent between these different responses.